The U.S. military has already shrunk significantly from its size at the height of President Ronald Reagan’s buildup in the 1980s. Now, with the war in Iraq over and the U.S. role in Afghanistan winding down, some are suggesting that the U.S. no longer needs so large a military. This would be a short-sighted decision that ignores the lessons of history.

Even with involvement in these conflicts ending, the U.S. military is being asked to do more, and it’s being asked to do it in every far-flung corner of the globe. From the Middle East to its growing role in Africa and Southeast Asia, the U.S. military will continue the fight against global terrorism.

The truth is the military does far more than fight the nation’s wars. In the Asia-Pacific region alone, 70,000 people die every year from natural disasters. The U.S. military is often one of the first responders on the scene, providing aid to the survivors. This not only promotes American interests–it’s the right thing to do.

One of the military’s most important–and cost-effective–missions is deterrence. By maintaining a large force in unstable parts of the world, America’s military helps keep a lid on regional tensions, reassuring allies and discouraging potential adversaries from taking hostile actions against the U.S.

The price of American strength is a military capable of protecting the nation’s interests worldwide, day in and day out. The problem with cutting military capabilities is that the cost of doing so is often invisible–until they are needed. National defense is a long-term but essential investment that provides enormous returns by saving American lives and treasure.

Mackenzie Eaglen is a resident fellow in the Marilyn Ware Center for Security Studies.